I'm building a 46" brushless Slow Stick (SS) from an NPS kit. This is what I have so far:

(See update on new items below.)

The instructions and specs in the GWS SS kit are not so good... perhaps "Lost in translation." And unfortunately the motor and ESC didn't come with any specs as well, which seems to be the case with Chinese stuff.

One nice thing about the slow stick, it flies well with just about any setup. I think the only part of the instructions I used was the cg.

I fly with a 2200 3 cell, and slid my servo tray all the way to the back of the plane againstthe tail so I could leave the battery up front against the wing between the motor. 300w is a lot of power, and a 8" prop is not very much on a 3 cell with 1000kv. I would probably try a 9X5 or 9X6 first and see how I liked it.

A guy in our park in Florida build planes for people. Just built a slow stick for a guy here with 2 ducted fan jets attached to the wings, tricycle gear etc. He took some pics to go on the Radical RC site eventually. The club I joined here use slow sticks in the winter to horse around with. One has a ducted fan jet underslung between the landing gear. I've never seen a wing flex so much and not snap.
Another altered his to do 3d flying. the entire rudder swivels on a center point on a shortened fuse. He can sure make that plane do some amazing things. Ive seen them with the wing tips cut off. more dihederal etc and some just plain old slow sticks lolling about.
The thing with the slow stick is it is very adaptable to mods. These fellas are all very good flyers and have modded the c##p out of theirs.
A fun plane to fly and learn on.

I use 3s 1300mah 25-35c turnigy's from hobby king and they work great with plenty of flight time I have a 950kv gws brushless motor. My 2200 3cell adds a lot of weight to the plane. I get around 30+ mins. flights from the 1300s. Try what you got on hand and see what you like best. I would run a bigger prop than the 8x4.7

I use 3s 1300mah 25-35c turnigy's from hobby king and they work great with plenty of flight time I have a 950kv gws brushless motor. My 2200 3cell adds a lot of weight to the plane. I get around 30+ mins. flights from the 1300s. Try what you got on hand and see what you like best. I would run a bigger prop than the 8x4.7

9x7 or 10x4.7? Perhaps I'll get a couple of each.. what do think the difference would be?

The slow stick doesn't need high torque or high speed servos this is an easy laid back and relaxed flyer to enjoy. I order mine from heads up with gws brushless motor included it's only 950kv and more than enough for the slow stick I was using 2s 900mah 25c batteries to fly it when I first got it. It's setup with 2 9g servos, 950kv, 30amp hobbywing esc, orange rx dsm receiver & the turnigy 3s 1300mah 25c batteries. The high torque servos might be over kill for the plane. and once it's built make sure when you give elev input that the elev. flap doesn't hit your tail rudder if so you will need to trim it with the tx.

part gws 1060 prop which is 10x6 should work. check out (heads up rc) that is the prop that comes in the ss/brushless kit. Did you not have a prop in your kit? Or are you wanting something besides the stock prop. With the 920kv the stock 10x6 will work fine. If you get new batteries later on for it go up to a 25c discharge it will give you a little more punch.

The slow stick doesn't need high torque or high speed servos this is an easy laid back and relaxed flyer to enjoy. I order mine from heads up with gws brushless motor included it's only 950kv and more than enough for the slow stick I was using 2s 900mah 25c batteries to fly it when I first got it.

I run the 10x6 prop you can go very slow or hit the throttle and pull off a few loops. Most of my flying is at 1/2 throttle. It don't take much to keep the ss in the air it has a good glide ability which is the main reason for the longer flight times.